Apparatus, system, and method for compressing a process fluid

ABSTRACT

A supersonic compressor including an inlet configured to receive and flow therethrough a process fluid. The supersonic compressor may further include a rotary shaft and a centrifugal impeller coupled therewith. The centrifugal impeller may be configured to impart energy to the process fluid received and to discharge the process fluid therefrom in at least a partially radial direction at an exit absolute Mach number of about one or greater. The supersonic compressor may further include a static diffuser circumferentially disposed about the centrifugal impeller and configured to receive the process fluid therefrom and convert the energy imparted. The supersonic compressor may further include a collector fluidly coupled to and configured to collect the process fluid exiting the diffuser, such that the supersonic compressor is configured to provide a compression ratio of at least about 8:1.

This application claims the benefit of U.S. Provisional patentapplication having Ser. No. 62/139,027, which was filed Mar. 27, 2015.The aforementioned patent application is hereby incorporated byreference in its entirety into the present application to the extentconsistent with the present application.

STATEMENT OF GOVERNMENT INTEREST

This invention was made with government support under GovernmentContract No. DOE-DE-FE0000493 awarded by the U.S. Department of Energy.The government has certain rights in the invention.

BACKGROUND

Compressors and systems including compressors have been developed andare utilized in a myriad of industrial processes (e.g., petroleumrefineries, offshore oil production platforms, and subsea processcontrol systems) to compress gas, typically by applying mechanicalenergy to the gas in a low pressure environment and transporting the gasto and compressing the gas within a higher pressure environment. Thecompressed gas may be utilized to perform work or for operation of oneor more downstream process components. As conventional compressors areincreasingly used in offshore oil production facilities and otherenvironments facing space constraints, there is an ever-increasingdemand for smaller, lighter, and more compact compressors. In additionto the foregoing, it is desirable for commercial purposes that thecompact compressors achieve higher compression ratios (e.g., 10:1 orgreater) while maintaining a compact arrangement.

In view of the foregoing, skilled artisans may often attempt to achievethe higher compression ratios by increasing the number of compressionstages within the compact compressor. Increasing the number ofcompression stages, however, increases the overall number of components(e.g., impellers and/or other intricate parts) required to achieve thedesired compressor throughput (e.g., mass flow) and pressure rise toachieve the higher compression ratios. Increasing the number ofcomponents required in these compact compressors may often increaselength requirements for the rotary shaft and/or increase distancerequirements between rotary shaft bearings. The imposition of theserequirements often results in larger, less compact compressors ascompared to compact compressors utilizing fewer compression stages.Further, in many cases, increasing the number of compression stages inthe compact compressors may still not provide the desired highercompression ratios, or if the desired compression ratios are achieved,the compact compressors may exhibit decreased efficiencies that make thecompact compressors commercially undesirable.

What is needed, therefore, is an efficient compression system thatprovides increased compression ratios in a compact arrangement that iseconomically and commercially viable.

SUMMARY

Embodiments of the disclosure may provide a supersonic compressor. Thesupersonic compressor may include a housing and an inlet coupled to orintegral with the housing and defining an inlet passageway configured toreceive and flow therethrough a process fluid. The supersonic compressormay also include a plurality of inlet guide vanes coupled to the housingand extending into the inlet passageway. The supersonic compressor mayfurther include a rotary shaft configured to be driven by a driver, anda centrifugal impeller coupled with the rotary shaft and fluidly coupledto the inlet passageway via a plurality of flow passages formed by thecentrifugal impeller. The centrifugal impeller may have a tip and beconfigured to impart energy to the process fluid received via the inletpassageway and to discharge the process fluid from the tip via theplurality of flow passages in at least a partially radial direction atan exit absolute Mach number of about one or greater. The supersoniccompressor may also include a balance piston configured to balance anaxial thrust generated by the centrifugal impeller. The supersoniccompressor may further include a static diffuser circumferentiallydisposed about the tip of the centrifugal impeller and bounded in partby a shroud wall and a hub wall defining an annular diffuser passagewaytherebetween. The static diffuser may be configured to receive theprocess fluid from the plurality of flow passages of the centrifugalimpeller and convert, within the annular diffuser passageway, the energyimparted. The supersonic compressor may further include a collectorfluidly coupled to the annular diffuser passageway and configured tocollect the process fluid exiting the annular diffuser passageway, suchthat the supersonic compressor is configured to provide a compressionratio of at least about 8:1.

Embodiments of the disclosure may further provide a compression system.The compression system may include a driver including a drive shaft, thedriver configured to provide the drive shaft with rotational energy, anda supersonic compressor operatively coupled to the driver via a rotaryshaft integral with or coupled with the drive shaft. The supersoniccompressor may include a compressor chassis and an inlet defining aninlet passageway configured to flow a process fluid therethrough. Theprocess fluid may have a first velocity and a first pressure energy. Thesupersonic compressor may also include a plurality of inlet guide vanespivotally coupled to the compressor chassis and extending into the inletpassageway, and a centrifugal impeller coupled with the rotary shaft andfluidly coupled to the inlet passageway via a plurality of flow passagesformed by the centrifugal impeller. The centrifugal impeller may have atip and may be configured to increase the first velocity and the firstpressure energy of the process fluid received via the inlet passagewayand to discharge the process fluid from the tip via the plurality offlow passages in at least a partially radial direction having a secondvelocity and a second pressure energy. The second velocity may be asupersonic velocity having an exit absolute Mach number of about one orgreater. The supersonic compressor may further include a static diffusercircumferentially disposed about the tip of the centrifugal impeller anddefining an annular diffuser passageway fluidly coupled to the pluralityof flow passages. The annular diffuser passageway may be configured toreceive and reduce the second velocity of the process fluid to a thirdvelocity and increase the second pressure energy to a third pressureenergy, the third velocity being a subsonic velocity. The supersoniccompressor may also include a discharge volute fluidly coupled to theannular diffuser passageway and configured to receive the process fluidflowing therefrom, such that the supersonic compressor is configured toprovide a compression ratio of at least about 8:1.

Embodiments of the disclosure may further provide a method forcompressing a process fluid. The method may include driving a rotaryshaft of a supersonic compressor via a driver operatively coupled withthe supersonic compressor. The method may also include establishing afluid property of the process fluid flowing through an inlet passagewaydefined by an inlet of the supersonic compressor via at least onemoveable inlet guide vane pivotally coupled to a housing of thesupersonic compressor and extending into the inlet passageway. Themethod may further include rotating a centrifugal impeller mounted aboutthe rotary shaft, such that the process fluid flowing though the inletpassageway of the supersonic compressor is drawn into the centrifugalimpeller and discharged from a tip of the centrifugal impeller via aplurality of flow passages. The discharged process fluid may have asupersonic velocity with an exit absolute Mach number of about 1.0 orgreater. The method may also include flowing the discharged processfluid having a supersonic velocity through an annular diffuserpassageway defined by a static diffuser and fluidly coupled to theplurality of flow passages such that a pressure energy of the dischargedprocess fluid is increased, thereby compressing the discharged processfluid at a compression ratio of about 8:1 or greater.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying Figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale. In fact, the dimensions of the variousfeatures may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 illustrates a schematic view of an exemplary compression system,according to one or more embodiments.

FIG. 2 illustrates a cross-sectional view of an exemplary compressor,which may be included in the compression system of FIG. 1, according toone or more embodiments.

FIG. 3 illustrates a perspective view of an exemplary impeller, whichmay be included in the compressor of FIG. 2, according to one or moreembodiments.

FIG. 4 illustrates a front view of a portion of the impeller of FIG. 3and a portion of an exemplary vaneless static diffuser that may beincluded in the compressor of FIG. 2, according to one or moreembodiments.

FIG. 5 illustrates a front view of a portion of the impeller of FIG. 3and a portion of an exemplary vaned static diffuser that may be includedin the compressor of FIG. 2, according to one or more embodiments.

FIG. 6 is a flowchart depicting an exemplary method for compressing aprocess fluid, according to one or more embodiments.

DETAILED DESCRIPTION

It is to be understood that the following disclosure describes severalexemplary embodiments for implementing different features, structures,or functions of the invention. Exemplary embodiments of components,arrangements, and configurations are described below to simplify thepresent disclosure; however, these exemplary embodiments are providedmerely as examples and are not intended to limit the scope of theinvention. Additionally, the present disclosure may repeat referencenumerals and/or letters in the various exemplary embodiments and acrossthe Figures provided herein. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various exemplary embodiments and/or configurationsdiscussed in the various Figures. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact.Finally, the exemplary embodiments presented below may be combined inany combination of ways, i.e., any element from one exemplary embodimentmay be used in any other exemplary embodiment, without departing fromthe scope of the disclosure.

Additionally, certain terms are used throughout the followingdescription and claims to refer to particular components. As one skilledin the art will appreciate, various entities may refer to the samecomponent by different names, and as such, the naming convention for theelements described herein is not intended to limit the scope of theinvention, unless otherwise specifically defined herein. Further, thenaming convention used herein is not intended to distinguish betweencomponents that differ in name but not function. Additionally, in thefollowing discussion and in the claims, the terms “including” and“comprising” are used in an open-ended fashion, and thus should beinterpreted to mean “including, but not limited to.” All numericalvalues in this disclosure may be exact or approximate values unlessotherwise specifically stated. Accordingly, various embodiments of thedisclosure may deviate from the numbers, values, and ranges disclosedherein without departing from the intended scope. Furthermore, as it isused in the claims or specification, the term “or” is intended toencompass both exclusive and inclusive cases, i.e., “A or B” is intendedto be synonymous with “at least one of A and B,” unless otherwiseexpressly specified herein.

FIG. 1 illustrates a schematic view of an exemplary compression system100, according to one or more embodiments. The compression system 100may include one or more compressors 102 (one is shown) configured topressurize a process fluid. In an exemplary embodiment, the compressionsystem 100 may have a compression ratio of at least about 6:1 orgreater. For example, the compression system 100 may compress theprocess fluid to a compression ratio of about 6:1, about 6.1:1, about6.2:1, about 6.3:1, about 6.4:1, about 6.5:1, about 6.6:1, about 6.7:1,about 6.8:1, about 6.9:1, about 7:1, about 7.1:1, about 7.2:1, about7.3:1, about 7.4:1, about 7.5:1, about 7.6:1, about 7.7:1, about 7.8:1,about 7.9:1, about 8:1, about 8.1:1, about 8.2:1, about 8.3:1, about8.4:1, about 8.5:1, about 8.6:1, about 8.7:1, about 8.8:1, about 8.9:1,about 9:1, about 9.1:1, about 9.2:1, about 9.3:1, about 9.4:1, about9.5:1, about 9.6:1, about 9.7:1, about 9.8:1, about 9.9:1, about 10:1,about 10.1:1, about 10.2:1, about 10.3:1, about 10.4:1, about 10.5:1,about 10.6:1, about 10.7:1, about 10.8:1, about 10.9:1, about 11:1,about 11.1:1, about 11.2:1, about 11.3:1, about 11.4:1, about 11.5:1,about 11.6:1, about 11.7:1, about 11.8:1, about 11.9:1, about 12:1,about 12.1:1, about 12.2:1, about 12.3:1, about 12.4:1, about 12.5:1,about 12.6:1, about 12.7:1, about 12.8:1, about 12.9:1, about 13:1,about 13.1:1, about 13.2:1, about 13.3:1, about 13.4:1, about 13.5:1,about 13.6:1, about 13.7:1, about 13.8:1, about 13.9:1, about 14:1, orgreater.

The compression system 100 may also include, amongst other components, adriver 104 operatively coupled to the compressor 102 via a drive shaft106. The driver 104 may be configured to provide the drive shaft 106with rotational energy. In an exemplary embodiment, the drive shaft 106may be integral with or coupled with a rotary shaft 108 of thecompressor 102, such that the rotational energy of the drive shaft 106is imparted to the rotary shaft 108. The drive shaft 106 may be coupledwith the rotary shaft 108 via a gearbox (not shown) including aplurality of gears configured to transmit the rotational energy of thedrive shaft 106 to the rotary shaft 108 of the compressor 102, such thatthe drive shaft 106 and the rotary shaft 108 may spin at the same speed,substantially similar speeds, or differing speeds and rotationaldirections.

The driver 104 may be a motor and more specifically may be an electricmotor, such as a permanent magnet motor, and may include a stator (notshown) and a rotor (not shown). It will be appreciated, however, thatother embodiments may employ other types of electric motors including,but not limited to, synchronous motors, induction motors, and brushed DCmotors. The driver 104 may also be a hydraulic motor, an internalcombustion engine, a steam turbine, a gas turbine, or any other devicecapable of driving the rotary shaft 108 of the compressor 102 eitherdirectly or through a power train.

In an exemplary embodiment, the compressor 102 may be a direct-inletcentrifugal compressor. In other embodiments, the compressor 102 may bea back-to-back compressor. The direct-inlet centrifugal compressor maybe, for example, a version of a Dresser-Rand Pipeline Direct Inlet (PDI)centrifugal compressor manufactured by the Dresser-Rand Company ofOlean, N.Y. The compressor 102 may have a center-hung rotorconfiguration or an overhung rotor configuration, as illustrated inFIG. 1. In an exemplary embodiment, the compressor 102 may be anaxial-inlet centrifugal compressor. In another embodiment, thecompressor 102 may be a radial-inlet centrifugal compressor. Aspreviously discussed, the compression system 100 may include one or morecompressors 102. For example, the compression system 100 may include aplurality of compressors (not shown). In another example, illustrated inFIG. 1, the compression system 100 may include a single compressor 102.The compressor 102 may be a supersonic compressor or a subsoniccompressor. In at least one embodiment, the compression system 100 mayinclude a plurality of compressors (not shown), and at least onecompressor of the plurality of compressors is a subsonic compressor. Inanother embodiment, illustrated in FIG. 1, the compression system 100includes a single compressor 102, and the single compressor 102 is asupersonic compressor.

The compressor 102 may include one or more stages (not shown). In atleast one embodiment, the compressor 102 may be a single-stagecompressor. In another embodiment, the compressor 102 may be amulti-stage centrifugal compressor. Each stage (not shown) of thecompressor 102 may be a subsonic compressor stage or a supersoniccompressor stage. In an exemplary embodiment, the compressor 102 mayinclude a single supersonic compressor stage. In another embodiment, thecompressor 102 may include a plurality of subsonic compressor stages. Inyet another embodiment, the compressor 102 may include a subsoniccompressor stage and a supersonic compressor stage. Any one or morestages of the compressor 102 may have a compression ratio greater thanabout 1:1. For example, any one or more stages of the compressor 102 mayhave a compression ratio of about 1.1:1, about 1.2:1, about 1.3:1, about1.4:1, about 1.5:1, about 1.6:1, about 1.7:1, about 1.8:1, about 1.9:1,about 2:1, about 2.1:1, about 2.2:1, about 2.3:1, about 2.4:1, about2.5:1, about 2.6:1, about 2.7:1, about 2.8:1, about 2.9:1, about 3:1,about 3.1:1, about 3.2:1, about 3.3:1, about 3.4:1, about 3.5:1, about3.6:1, about 3.7:1, about 3.8:1, about 3.9:1, about 4:1, about 4.1:1,about 4.2:1, about 4.3:1, about 4.4:1, about 4.5:1, about 4.6:1, about4.7:1, about 4.8:1, about 4.9:1, about 5:1, about 5.1:1, about 5.2:1,about 5.3:1, about 5.4:1, about 5.5:1, about 5.6:1, about 5.7:1, about5.8:1, about 5.9:1, about 6:1, about 6.1:1, about 6.2:1, about 6.3:1,about 6.4:1, about 6.5:1, about 6.6:1, about 6.7:1, about 6.8:1, about6.9:1, about 7:1, about 7.1:1, about 7.2:1, about 7.3:1, about 7.4:1,about 7.5:1, about 7.6:1, about 7.7:1, about 7.8:1, about 7.9:1, about8.0:1, about 8.1:1, about 8.2:1, about 8.3:1, about 8.4:1, about 8.5:1,about 8.6:1, about 8.7:1, about 8.8:1, about 8.9:1, about 9:1, about9.1:1, about 9.2:1, about 9.3:1, about 9.4:1, about 9.5:1, about 9.6:1,about 9.7:1, about 9.8:1, about 9.9:1, about 10:1, about 10.1:1, about10.2:1, about 10.3:1, about 10.4:1, about 10.5:1, about 10.6:1, about10.7:1, about 10.8:1, about 10.9:1, about 11:1, about 11.1:1, about11.2:1, about 11.3:1, about 11.4:1, about 11.5:1, 11 3.6:1, about11.7:1, about 11.8:1, about 11.9:1, about 12:1, about 12.1:1, about12.2:1, about 12.3:1, about 12.4:1, about 12.5:1, about 12.6:1, about12.7:1, about 12.8:1, about 12.9:1, about 13:1, about 13.1:1, about13.2:1, about 13.3:1, about 13.4:1, about 13.5:1, about 13.6:1, about13.7:1, about 13.8:1, about 13.9:1, about 14:1, or greater. In anexemplary embodiment, the compressor 102 may include a plurality ofcompressor stages, where a first stage (not shown) of the plurality ofcompressor stages may have a compression ratio of about 1.75:1 and asecond stage (not shown) of the plurality of compressor stages may havea compression ratio of about 6.0:1.

FIG. 2 illustrates a cross-sectional view of an embodiment of thecompressor 102, which may be included in the compression system 100 ofFIG. 1. As shown in FIG. 2, the compressor 102 includes a housing 110forming or having an axial inlet 112 defining an inlet passageway 114, astatic diffuser 116 fluidly coupled to the inlet passageway 114, and acollector 117 fluidly coupled to the static diffuser 116. Althoughillustrated as an axial inlet in FIG. 2, in one or more otherembodiments, the inlet 112 may be a radial inlet. The driver 104 may bedisposed outside of (as shown in FIG. 1) or within the housing 110, suchthat the housing 110 may have a first end, or compressor end, and asecond end (not shown), or driver end. The housing 110 may be configuredto hermetically seal the driver 104 and the compressor 102 within,thereby providing both support and protection to each component of thecompression system 100. The housing 110 may also be configured tocontain the process fluid flowing through one or more portions orcomponents of the compressor 102.

The drive shaft 106 of the driver 104 and the rotary shaft 108 of thecompressor 102 may be supported, respectively, by one or more radialbearings 118, as shown in FIG. 1 in an overhung configuration. Theradial bearings 118 may be directly or indirectly supported by thehousing 110, and in turn provide support to the drive shaft 106 and therotary shaft 108, which carry the compressor 102 and the driver 104during operation of the compression system 100. In one embodiment, theradial bearings 118 may be magnetic bearings, such as active or passivemagnetic bearings. In other embodiments, however, other types ofbearings (e.g., oil film bearings) may be used. In addition, at leastone axial thrust bearing 120 may be provided to manage movement of therotary shaft 108 in the axial direction. In an embodiment in which thedriver 104 and the compressor 102 are hermetically-sealed within thehousing 110, the thrust bearing 120 may be provided at or near the endof the rotary shaft 108 adjacent the compressor end of the housing 110.The axial thrust bearing 120 may be a magnetic bearing and may beconfigured to bear axial thrusts generated by the compressor 102.

As shown in FIG. 2, the axial inlet 112 defining the inlet passageway114 of the compressor 102 may include one or more inlet guide vanes 122of an inlet guide vane assembly configured to condition a process fluidflowing therethrough to achieve predetermined or desired fluidproperties and/or fluid flow attributes. Such fluid properties mayinclude flow pattern (e.g., swirl distribution), velocity, mass flowrate, pressure, temperature, and/or any suitable fluid property andfluid flow attribute to enable the compressor 102 to function asdescribed herein. The inlet guide vanes 122 may be disposed within theinlet passageway 114 and may be static or moveable, i.e., adjustable. Inan exemplary embodiment, a plurality of inlet guide vanes 122 may bearranged about a circumferential inner surface 124 of the axial inlet112 in a spaced apart orientation, each extending into the inletpassageway 114. The spacing of the inlet guide vanes 122 may beequidistant or may vary depending on the predetermined process fluidproperty and/or fluid flow attribute desired. With reference to shape,the inlet guide vanes 122 may be airfoil shaped, streamline shaped, orotherwise shaped and configured to at least partially impart the one ormore fluid properties and/or fluid flow attributes on the process fluidflowing through the inlet passageway 114.

In one or more embodiments, the inlet guide vanes 122 may be moveablycoupled to the housing 110 and disposed within the inlet passageway 114as disclosed in U.S. Pat. No. 8,632,302, the subject matter of which isincorporated by reference herein to the extent consistent with thepresent disclosure. The inlet guide vanes 122 may be further coupled toan annular inlet guide vane actuation member (not shown), such that uponactuation of the annular inlet vane actuation member, each of the inletguide vanes 122 coupled to the annular inlet guide vane actuation membermay pivot about the respective coupling to the housing 110, therebyadjusting the flow incident on components of the compressor 102. Asconfigured, the inlet guide vanes 122 may be adjusted withoutdisassembling the housing 110 in order to adjust the performance of thecompressor 102. Doing so without disassembly of the compressor 102 savestime and effort in optimizing the compressor 102 for a particularoperating condition. Furthermore, the impact of alternate vane angles onoverall flow range and/or peak efficiency may be assessed and optimizedfor increased performance, and a matrix of inlet guide vane angles maybe produced on a relatively short cycle time relative to conventionalcompressors such that the data may be analyzed to determine the bestcombination of inlet guide vane angles for any given application.

The compressor 102 may include a centrifugal impeller 126 configured torotate about a center axis 128 within the housing 110. In an exemplaryembodiment, the centrifugal impeller 126 includes a hub 130 and is openor “unshrouded.” In another embodiment, the centrifugal impeller 126 maybe a shrouded impeller. The hub 130 may include a first meridional endportion 132, generally referred to as the eye of the centrifugalimpeller 126, and a second meridional end portion 134 having a discshape, the outer perimeter of the second meridional end portion 134generally referred to as the tip 136 of the centrifugal impeller 126.The disc-shaped, second meridional end portion 134 may taper inwardly tothe first meridional end portion 132 having an annular shape. The hub130 may define a bore 138 configured to receive a coupling member 140,such as a tie-bolt, to couple the centrifugal impeller 126 to the rotaryshaft 108. In another embodiment, the bore 138 may be configured toreceive the rotary shaft 108 extending therethrough.

As shown in FIG. 2, the compressor 102 may include a balance piston 142configured to balance an axial thrust generated by the centrifugalimpeller 126 during operation. In an exemplary embodiment, the balancepiston 142 may be integral with the centrifugal impeller 126, such thatthe balance piston 142 and the centrifugal impeller 126 are formed froma single or unitary piece. In another embodiment, the balance piston 142and the centrifugal impeller 126 may be separate components. Forexample, the balance piston 142 and the centrifugal impeller 126 may beseparate annular components coupled with one another. One or more seals,e.g., labyrinth seals, may be implemented to isolate the balance piston142 from external contaminants or lubricants.

The centrifugal impeller 126 may be operatively coupled to the rotaryshaft 108 such that the rotary shaft 108, when acted upon by the driver104 via the drive shaft 106, rotates, thereby causing the centrifugalimpeller 126 to rotate such that process fluid flowing into the inletpassageway 114 is drawn into the centrifugal impeller 126 andaccelerated to the tip 136, or periphery, of the centrifugal impeller126, thereby increasing the velocity of the process fluid. In one ormore embodiments, the process fluid at the tip 136 of the centrifugalimpeller 126 may be subsonic and have an absolute Mach number less thanone. For example, the process fluid at the tip 136 of the centrifugalimpeller 126 may have an exit absolute Mach number less than one, lessthan 0.9, less than 0.8, less than 0.7, less than 0.6, or less than 0.5.Accordingly, in such embodiments, the compressor 102 discussed hereinmay be “subsonic,” as the centrifugal impeller 126 may be configured torotate about the center axis 128 at a speed sufficient to provide theprocess fluid at the tip 136 thereof with an exit absolute Mach numberof less than one.

In one or more embodiments, the process fluid at the tip 136 of thecentrifugal impeller 126 may be supersonic and have an exit absoluteMach number of one or greater. For example, the process fluid at the tip136 of the centrifugal impeller 126 may have an exit absolute Machnumber of at least one, at least 1.1, at least 1.2, at least 1.3, atleast 1.4, or at least 1.5. Accordingly, in such embodiments, thecompressor 102 discussed herein may be “supersonic,” as the centrifugalimpeller 126 may be configured to rotate about the center axis 128 at aspeed sufficient to provide the process fluid at the tip 136 thereofwith an exit absolute Mach number of one or greater or with a fluidvelocity greater than the speed of sound. In a supersonic compressor ora stage thereof, the rotational or tip speed of the centrifugal impeller126 may be about 500 meters per second (m/s) or greater. For example,the tip speed of the centrifugal impeller 126 may be about 510 m/s,about 520 m/s, about 530 m/s, about 540 m/s, about 550 m/s, about 560m/s, or greater.

Referring now to FIGS. 3-5, with continued reference to FIG. 2, FIG. 3illustrates a perspective view of the centrifugal impeller 126 that maybe included in the compressor 102, according to one or more embodiments.FIG. 4 illustrates a front view of a portion of the centrifugal impeller126 of FIG. 3 and a portion of the static diffuser 116 that may beincluded in the compressor 102 of FIG. 2, according to one or moreembodiments. FIG. 5 illustrates a front view of a portion of thecentrifugal impeller 126 of FIG. 3 and a portion of another staticdiffuser 216 that may be included in the compressor 102 of FIG. 2 andutilized in place of the static supersonic diffuser 116, according toone or more embodiments.

As shown in FIG. 2 and more clearly in FIGS. 3-5, the centrifugalimpeller 126 may include a plurality of aerodynamic surfaces or blades144 a,b coupled or integral with the hub 130 and configured to increasethe velocity and energy of the process fluid. As illustrated in FIGS.3-5, the blades 144 a,b of the centrifugal impeller 126 may be curved,such that the process fluid may be urged in a tangential and radialdirection by the centrifugal force through a plurality of flow passages146, 148 formed by the blades 144 a,b and discharged from the blade tipsof the centrifugal impeller 126 (cumulatively, the tip 136 of thecentrifugal impeller 126) in at least partially radial directions thatextend 360 degrees around the centrifugal impeller 126. It will beappreciated that the contour or amount of curvature of the blades 144a,b is not limited to the shaping illustrated in FIGS. 3-5 and may bedetermined based, at least in part, on desired operating parameters.

The plurality of blades 144 a,b may include main blades 144 a spacedequidistantly apart and circumferentially about the center axis 128.Each main blade 144 a may extend from a leading edge 150 disposedadjacent the first meridional end portion 132 of the centrifugalimpeller 126 to a trailing edge 152 disposed adjacent the secondmeridional end portion 134 of the centrifugal impeller 126. Further,based on rotation of the centrifugal impeller 126, each main blade 144 amay define a pressure surface on one side 154 of the main blade 144 aand a suction surface on the opposing side 156 of the main blade 144 a.As shown most clearly in FIG. 3, the centrifugal impeller 126 mayinclude thirteen main blades 144 a; however, other embodiments includingmore than or less than thirteen main blades are contemplated herein. Thenumber of main blades 144 a may be determined based, at least in part,on desired operating parameters.

The plurality of blades 144 a,b may also include one or more splitterblades 144 b configured to reduce aerodynamic choking conditions thatmay occur in the compressor 102 depending on the number of blades 144a,b employed with respect to the centrifugal impeller 126. The splitterblades 144 b may be spaced equidistantly apart and circumferentiallyabout the center axis 128. Each splitter blade 144 b may extend from aleading edge 158, meridionally spaced and downstream from the firstmeridional end portion 132, to a trailing edge 160 disposed adjacent thesecond meridional end portion 134 of the centrifugal impeller 126. Theleading edge 158 of each splitter blade 144 b may be disposedmeridionally outward from the leading edges 150 of the main blades 144 asuch that the respective leading edges 150, 158 of the main blades 144 aand splitter blades 144 b are staggered and not coplanar. Further, basedon rotation of the centrifugal impeller 126, each splitter blade 144 bmay define a pressure surface on one side 162 of the splitter blade 144b and a suction surface on the opposing side 164 of the splitter blade144 b.

As most clearly illustrated in FIGS. 2 and 3, each of the main blades144 a and the splitter blades 144 b extends meridionally from the secondmeridional end portion 134 of the centrifugal impeller 126 toward thefirst meridional end portion 132 thereof. The configuration of therespective meridional extents of the main blades 144 a and the splitterblades 144 b may be substantially similar proximal the respectivetrailing edges 152, 160 of the main blades 144 a and the splitter blades144 b. The configuration of the respective meridional extents of themain blades 144 a and the splitter blades 144 b may differ from thesecond meridional end portion 134 to the respective leading edges 150,158 of the main blades 144 a and the splitter blades 144 b. In anexemplary embodiment, the meridional extent of each of the main blades144 a may be greater than the meridional extent of each of the splitterblades 144 b, such that the respective leading edges 158 of the splitterblades 144 b may be disposed meridionally offset toward the secondmeridional end portion 134 of the centrifugal impeller 126 from therespective leading edges 150 of the main blades 144 a.

The splitter blades 144 b and main blades 144 a may be arrangedcircumferentially about the center axis 128 in a pattern such that asplitter blade 144 b is disposed between adjacent main blades 144 a. Asarranged, each splitter blade 144 b may be disposed between the pressuresurface side 154 of an adjacent main blade 144 a and the suction surfaceside 156 of the other adjacent main blade 144 a. Further, the splitterblades 144 b may be “clocked” with respect to the main blades 144 a,such that each splitter blade 144 b is circumferentially offset or notequidistant from the respective adjacent main blades 144 a and thus isnot circumferentially centered between the adjacent main blades 144 a.By clocking the splitter blades 144 b, e.g., displacing the splitterblades 144 b from a position equidistant from adjacent main blades 144a, the operating characteristics of the centrifugal impeller 126 may beimproved.

In one or more embodiments, the splitter blades 144 b and main blades144 a may be arranged circumferentially about the center axis 128 in apattern such that a plurality of splitter blades 144 b may be disposedbetween adjacent main blades 144 a. Accordingly, in one embodiment, atleast two splitter blades 144 b are disposed between adjacent mainblades 144 a. The leading edges 158 of the respective splitter blades144 b may be offset meridionally from one another such that therespective leading edges 158 of the splitter blades 144 b are staggeredand not coplanar.

As positioned between the adjacent main blades 144 a, each splitterblade 144 b may be oriented such that the splitter blade 144 b iscanted, such that the leading edge 158 of the splitter blade 144 b iscircumferentially offset from a position equidistant from the adjacentmain blades 144 a a different percentage amount than the trailing edge160 of the splitter blade 144 b. Accordingly, in an exemplaryembodiment, the leading edge 158 of the splitter blade 144 b may bedisplaced from a position equidistant from the adjacent main blades 144a by a distance of a first percentage amount of one half the angulardistance θ between the adjacent main blades 144 a. The trailing edge 160of the splitter blade 144 b may be displaced from the positionequidistant the adjacent main blades 144 a by a distance of a secondpercentage amount of one half the angular distance 8 between theadjacent main blades 144 a.

In an exemplary embodiment, the first percentage amount may be greaterthan the second percentage amount. In another embodiment, the firstpercentage amount may be less than the second percentage amount. Forexample, the difference in displacement between the leading edge 158 andthe trailing edge 160 from the position equidistant the adjacent mainblades 144 a may be a percentage amount of about one percent, about twopercent, about three percent, about four percent, about five percent,about ten percent, about fifteen percent, about twenty percent, orgreater. In another example, the difference in displacement between theleading edge 158 and the trailing edge 160 from the position equidistantthe adjacent main blades 144 a may be a percentage amount of betweenabout one percent and about two percent, about three percent and aboutfive percent, about five percent and about ten percent, or about tenpercent and about twenty percent. The differences in distance related tothe percentage amounts, e.g., the amount the splitter blade 144 b iscanted, may be determined based, at least in part, on desired operatingparameters.

As shown in FIGS. 3-5, a plurality of flow passages 146, 148 may beformed between the splitter blades 144 b and the adjacent main blades144 a as arranged about the center axis 128. In an exemplary embodiment,the plurality of flow passages 146, 148 may include a first flow passage146 formed between the pressure surface side 162 of the splitter blade144 b and the suction surface side 156 of one of the adjacent mainblades 144 a and a second flow passage 148 between the suction surfaceside 164 of the splitter blade 144 b and the pressure surface side 154of the other adjacent main blade 144 a. The mass flow of the processfluid through the first and second flow passages 146, 148 may bedetermined based on the displacement of the splitter blade 144 b inrelation to the adjacent main blades 144 b. For example, it has beendetermined that disposing the splitter blade 144 b equidistantly betweenthe adjacent main blades 144 a may not result in equal mass flow throughthe first flow passage 146 and the second flow passage 148. Accordingly,in an exemplary embodiment, the splitter blade 144 b may becircumferentially offset from a position centered between adjacent mainblades 144 a, such that the suction surface side 164 of the splitterblade 144 b is disposed in a direction closer to the pressure surfaceside 154 of one of the adjacent main blades 144 a and further from thesuction surface side 156 of the other adjacent main blade 144 a, therebysubstantially equalizing the mass flow through the respective flowpassages 146, 148.

As will be appreciated by those of skill in the art, the desireddisplacement of the splitter blades 144 b may depend on various factors,such as the shape of the blades 144 a,b, the angle of incidence of theblades 144 a,b, the size of the blades 144 a,b and of the centrifugalimpeller 126, the operating speed range, etc. However, the displacementnecessary to equalize the mass flow through the first flow passage 146and the second flow passage 148 may be determined for a given design ofthe centrifugal impeller 126 and corresponding blades 144 a,b bymeasurement of the mass flow, such as by use of a mass flow meter.

As shown in FIG. 2, the compressor 102 may include a shroud 170 coupledto the housing 110 and disposed adjacent the plurality of blades 144 a,bof the centrifugal impeller 126. In particular, a surface 172 of theshroud 170 may include an abradable material and may be contoured tosubstantially align with the silhouette of the plurality of blades 144a,b, thus substantially reducing leakage flow of the process fluid in agap defined therebetween. The abradable material is arranged on thesurface 172 of the shroud 170 and configured to be deformed and/orremoved therefrom during incidental contact of the rotating centrifugalimpeller 126 with the abradable material of the stationary shroud 170during axial movement of the rotary shaft 108, thereby preventing damageto the blades 144 a,b and resulting in a loss of a sacrificial amount ofthe abradable material.

In an embodiment, illustrated most clearly in FIG. 4 with continuedreference to FIG. 2, the compressor 102 may include the static diffuser116 fluidly coupled to the axial inlet 112 and configured to receive theradial process fluid flow exiting the tip 136 of the centrifugalimpeller 126. In an exemplary embodiment, the static diffuser 116 may bea vaneless diffuser. The static diffuser 116 may be configured toconvert kinetic energy of the process fluid from the centrifugalimpeller 126 into increased static pressure. In an exemplary embodiment,the static diffuser 116 may be located downstream of the centrifugalimpeller 126 and may be statically disposed circumferentially about theperiphery, or tip 136, of the centrifugal impeller 126.

The static diffuser 116 may be coupled with or integral with the housing110 of the compressor 102 and may form an annular diffuser passageway174 having an inlet end 176 adjacent the tip 136 of the centrifugalimpeller 126 and a radially outer outlet end 178. In an exemplaryembodiment, the annular diffuser passageway 174 may be formed, at leastin part, by portions of the housing 110, namely a shroud wall 180 and ahub wall 182, forming the confining sidewalls of the static diffuser116. The shroud wall 180 and the hub wall 182 may each be a straightwall or a contoured wall, such that the annular diffuser passageway 174may be formed from straight walls, contoured walls, or a combinationthereof. In addition, the annular diffuser passageway 174 may have areduced width as the shroud wall 180 and the hub wall 182 extendradially outward. Such a “pinched” diffuser may provide for lower chokeand surge limits and, thus, improve the efficiency of the centrifugalimpeller 126.

In another embodiment, illustrated most clearly in FIG. 5 with continuedreference to FIG. 2, a static diffuser 216 may be utilized in thecompressor 102 in place of the static diffuser 116 disclosed above. Thestatic diffuser 216 illustrated in FIG. 5 may be similar in somerespects to the static diffuser 116 described above and therefore may bebest understood with reference to the description of FIGS. 2 and 4,where like numerals may designate like components and will not bedescribed again in detail. The static diffuser 216 may be fluidlycoupled to the axial inlet 112 and configured to receive the radialprocess fluid flow exiting the centrifugal impeller 126.

The static diffuser 216 may be configured to convert kinetic energy ofthe process fluid from the centrifugal impeller 126 into increasedstatic pressure. In an exemplary embodiment, the static diffuser 216 maybe located downstream of the centrifugal impeller 126 and may bestatically disposed circumferentially about the periphery, or tip 136,of the centrifugal impeller 126. The static diffuser 216 may be coupledwith or integral with the housing 110 of the compressor 102 and mayfurther form the annular diffuser passageway 174 having the inlet end176 adjacent the tip 136 of the centrifugal impeller 126 and theradially outer outlet end 178. In an exemplary embodiment, the annulardiffuser passageway 174 may be formed, at least in part, by the shroudwall 180 and the hub wall 182 of the housing 110.

In an exemplary embodiment, the static diffuser 216 may be a vaneddiffuser, e.g., wedge diffuser, or a vaned diffuser as shown in FIG. 5.The static diffuser 216 may have a plurality of diffuser vanes 184, 186arranged in a plurality of concentric rings 188, 190 about the centeraxis 128 and extending from the shroud wall 180 or the hub wall 182 orfrom both the shroud wall 180 and the hub wall 182 of the staticdiffuser 216. As shown in FIG. 5, the plurality of diffuser vanes 184,186 may include first row vanes 184 arranged in a first ring 188 aboutthe center axis 128 and extending from the hub wall 182 of the staticdiffuser 216. The first row vanes 184 each include a leading edge 192disposed proximal the inlet end 176 and a trailing edge 194 radially andcircumferentially offset from the leading edge 192. The first row vanes184 may be low solidity diffuser vanes, where the chord to pitch ratioof the first row vanes 184 is less than one. As provided herein,diffuser vanes having a chord to pitch ratio of less than one arereferred to as low solidity diffuser vanes. In the illustratedembodiment of FIG. 5, the first ring 188 includes seventeen low soliditydiffuser vanes; however, embodiments including more or less thanseventeen low solidity diffuser vanes are contemplated herein. Each ofthe first row vanes 184 may be airfoils or shaped substantially similarthereto.

As shown in FIG. 5, the plurality of diffuser vanes 184, 186 may includesecond row vanes 186 arranged in a second ring 190 about the center axis128 and extending from the hub wall 182 of the static diffuser 216. Theplurality of diffuser vanes 184, 186 is arranged in tandem, such thatthe second ring 190 of second row vanes 186 is disposed radially outwardfrom the first ring 188 of first row vanes 184. The second row vanes 186include respective leading edges 196 disposed proximal the trailingedges 194 of the first row vanes 184 and respective trailing edges 198radially and circumferentially offset from the leading edges 196. Thesecond row vanes 186 may have a greater solidity than the first rowvanes 184, where the chord to pitch ratio of the second row vanes 186 isgenerally greater than the chord to pitch ratio of the first row vanes184. In an exemplary embodiment, the chord to pitch ratio of the secondrow vanes 186 is one or greater. As provided herein, diffuser vaneshaving a chord to pitch ratio of one or greater are referred to as highsolidity diffuser vanes. In the illustrated embodiment of FIG. 5, thesecond ring 190 includes a multiple of the number of first row vanes184, and more specifically, twice the number of first row vanes 184.Thus, in an embodiment in which the first ring 188 includes seventeenfirst row vanes 184, the second ring 190 may include thirty-fourdiffuser vanes; however, embodiments including more or less thanthirty-four diffuser vanes are contemplated herein. Each of the secondrow vanes 186 may be airfoils or shaped substantially similar thereto.

In an exemplary embodiment, the first row vanes 184 of the first ring188 may be proximal the tip 136 of the centrifugal impeller 126 and maybe spaced therefrom via an inner vaneless space 200. Accordingly, theinner vaneless space 200 may be provided between the centrifugalimpeller tip diameter 202 and the leading edge diameter 204 of the firstring 188. In an exemplary embodiment, the inner vaneless space 200 maybe formed from the leading edge diameter 204 being about five to aboutten percent greater than the centrifugal impeller tip diameter 202. Inanother embodiment, the inner vaneless space 200 may be formed from theleading edge diameter 204 being about six to about eight percent greaterthan the centrifugal impeller tip diameter 202. Similarly, an outervaneless space 206 may be provided between the diameter 208 formed bythe trailing edges 194 of the first row vanes 184 of the first ring 188and the diameter 210 of the leading edges 196 of the second row vanes186 of the second ring 190. In an exemplary embodiment, the outervaneless space 206 may be formed from the leading edge diameter 210 ofthe second ring 190 being about five to about ten percent greater thanthe trailing edge diameter 208 of the first ring 188. In anotherembodiment, the outer vaneless space 206 may be formed from the leadingedge diameter 210 of the second ring 190 being about six to about eightpercent greater than the trailing edge diameter 208 of the first ring188.

In an exemplary embodiment, the incidence of the first row vanes 184 ofthe first ring 188 may be determined for controlling the exit absoluteMach number and reducing supersonic flow introduced at the inlet end 176of the static diffuser 216 to a subsonic flow at the trailing edges 194of the first ring 188. As configured, shock waves created by the leadingedges 192 of the first ring 188 do not propagate to the second row vanes186; however, the leading edges 192 of the first ring 188 provide for acommunication path from the downstream portion of the static diffuser216 toward an upstream portion of the centrifugal impeller 126 to backpressure the centrifugal impeller 126, thereby obtaining a wider range.The incidence of the second row vanes 186 of the second ring 190 may bedetermined by placing the second ring 190 in the “shadow” or flow pathof the first ring 188. Accordingly, the second row vanes 186 may bearranged such that two second row vanes 186 are provided in the wake ofeach first row vane 184 and are provided to alter the direction of theprocess fluid flow.

In another embodiment, the static diffuser 216 may include third rowvanes (not shown) arranged in a third ring (not shown) about the centeraxis 128 and disposed radially outward of the first ring 188 and thesecond ring 190, where the first ring 188, the second ring 190, and thethird ring are concentric. The third row vanes may have a chord to pitchratio less than the chord to pitch ratio of the second row vanes 186 ofthe second ring 190. In another embodiment, the third row vanes may havea chord to pitch ratio substantially equal to the chord to pitch ratioof the first row vanes 184 of the first ring 188. The third row vanesmay be configured to provide additional turning of the process fluidflow.

As discussed above, in one or more embodiments, the compressor 102provided herein may be referred to as “supersonic” because thecentrifugal impeller 126 may be designed to rotate about the center axis128 at high speeds such that a moving process fluid encountering theinlet end 176 of the static diffuser 116 is said to have a fluidvelocity which is above the speed of sound of the process fluid beingcompressed. Thus, in an exemplary embodiment, the moving process fluidencountering the inlet end 176 of the static diffuser 116 may have anexit absolute Mach number of about one or greater. However, to increasetotal energy of the fluid system, the moving process fluid encounteringthe inlet end 176 of the static diffuser 116 may have an exit absoluteMach number of at least about 1.1, at least about 1.2, at least about1.3, at least about 1.4, or at least about 1.5. In another example, theprocess fluid at the tip 136 of the centrifugal impeller 126 may have anexit absolute Mach number from about 1.1 to about 1.5, or about 1.2 toabout 1.4.

The process fluid flow leaving the outlet end 178 of the static diffuser116, 216 may flow into the collector 117, as most clearly seen in FIG.2. The collector 117 may be configured to gather the process fluid flowfrom the static diffuser 116, 216 and to deliver the process fluid flowto a downstream pipe and/or process component (not shown). In anexemplary embodiment, the collector 117 may be a discharge volute orspecifically, a scroll-type discharge volute. In another embodiment, thecollector 117 may be a plenum. The collector 117 may be furtherconfigured to increase the static pressure of the process fluid flow byconverting the kinetic energy of the process fluid to static pressure.The collector 117 may have a round tongue (not shown). In anotherembodiment, the collector may have a sharp tongue (not shown). It willbe appreciated that the tongue of the collector 117 may form othershapes known to those of ordinary skill in the art without varying fromthe scope of this disclosure.

One or more exemplary operational aspects of an exemplary compressionsystem 100 will now be discussed with continued reference to FIGS. 1-5.A process fluid may be provided from an external source (not shown),having a low pressure environment, to the compression system 100. Thecompression system 100 may include, amongst other components, thecompressor 102 having the centrifugal impeller 126 coupled with therotary shaft 108 and the static diffuser 116 disposed circumferentiallyabout the rotating centrifugal impeller 126. In another embodiment, thecompression system 100 may include, amongst other components, thecompressor 102 having the centrifugal impeller 126 coupled with therotary shaft 108 and the static diffuser 216 disposed circumferentiallyabout the rotating centrifugal impeller 126.

The process fluid may be drawn into the axial inlet 112 of thecompressor 102 with a velocity ranging, for example, from about Mach0.05 to about Mach 0.40. The process fluid may flow through the inletpassageway 114 defined by the axial inlet 112 and across the inlet guidevanes 122 extending into the inlet passageway 114. The process fluidflowing across the inlet guide vanes 122 may be provided with anincreased velocity and imparted with at least one fluid property (e.g.,swirl) prior to be being drawn into the rotating centrifugal impeller126. The inlet guide vanes 122 may be adjusted in order to vary the oneor more fluid properties imparted to the process fluid.

The process fluid may be drawn into the rotating centrifugal impeller126 and may contact the curved centrifugal impeller blades 144 a,b, suchthat the process fluid may be accelerated in a tangential and radialdirection by centrifugal force and may be discharged from the flowpassages 146, 148 via the blade tips of the centrifugal impeller 126(cumulatively, the tip 136 of the centrifugal impeller 126) in at leastpartially radial directions that extend 360 degrees around the rotatingcentrifugal impeller 126. The rotating centrifugal impeller 126increases the velocity and static pressure of the process fluid, suchthat the velocity of the process fluid discharged from the blade tips(cumulatively, the tip 136 of the centrifugal impeller 126) may besupersonic in some embodiments and have an exit absolute Mach number ofat least about one, at least about 1.1, at least about 1.2, at leastabout 1.3, at least about 1.4, or at least about 1.5.

In an embodiment, the static diffuser 116 may be disposedcircumferentially about the periphery, or tip 136, of the centrifugalimpeller 126 and may be coupled with or integral with the housing 110 ofthe compressor 102. In another embodiment, the static diffuser 216 maybe disposed circumferentially about the periphery, or tip 136, of thecentrifugal impeller 126 and may be coupled with or integral with thehousing 110 of the compressor 102. The radial process fluid flowdischarged from the rotating centrifugal impeller 126 may be received bythe static diffuser 116, 216 such that the velocity of the flow ofprocess fluid discharged from the tip 136 of the rotating centrifugalimpeller 126 is substantially similar to the velocity of the processfluid entering the inlet end 176 of the static diffuser 116, 216.Accordingly, the process fluid may enter the inlet end 176 of the staticdiffuser 116, 216 with a supersonic velocity having, for example, anexit absolute Mach number of at least one, and correspondingly, may bereferred to as supersonic process fluid.

The velocity of the supersonic process fluid flowing into the inlet end176 of the static diffuser 116, 216 decreases with increasing radius ofthe annular diffuser passageway 174 as the process fluid flows from theinlet end 176 to the radially outer outlet end 178 of the staticdiffuser 116, 216 as the velocity head is converted to static pressure.In at least one embodiment including the static diffuser 216, thetangential velocity of the supersonic process fluid may decelerate fromsupersonic to subsonic velocities across the first row vanes 184 withoutshock losses. The static diffuser 116, 216 may reduce the velocity andincrease the pressure energy of the process fluid.

The process fluid exiting the static diffuser 116, 216 may have asubsonic velocity and may be fed into the collector 117 or dischargevolute. The collector 117 may increase the static pressure of theprocess fluid by converting the remaining kinetic energy of the processfluid to static pressure. The process fluid may then be routed toperform work or for operation of one or more downstream processes orcomponents (not shown).

The process fluid pressurized, circulated, contained, or otherwiseutilized in the compression system 100 may be a fluid in a liquid phase,a gas phase, a supercritical state, a subcritical state, or anycombination thereof. The process fluid may be a mixture, or processfluid mixture. The process fluid may include one or more high molecularweight process fluids, one or more low molecular weight process fluids,or any mixture or combination thereof. As used herein, the term “highmolecular weight process fluids” refers to process fluids having amolecular weight of about 30 grams per mole (g/mol) or greater.Illustrative high molecular weight process fluids may include, but arenot limited to, hydrocarbons, such as ethane, propane, butanes,pentanes, and hexanes. Illustrative high molecular weight process fluidsmay also include, but are not limited to, carbon dioxide (CO₂) orprocess fluid mixtures containing carbon dioxide. As used herein, theterm “low molecular weight process fluids” refers to process fluidshaving a molecular weight less than about 30 g/mol. Illustrative lowmolecular weight process fluids may include, but are not limited to,air, hydrogen, methane, or any combination or mixtures thereof.

In an exemplary embodiment, the process fluid or the process fluidmixture may be or include carbon dioxide. The amount of carbon dioxidein the process fluid or the process fluid mixture may be at least about80%, at least about 85%, at least about 90%, at least about 95%, atleast about 96%, at least about 97%, at least about 98%, at least about99%, or greater by volume. Utilizing carbon dioxide as the process fluidor as a component or part of the process fluid mixture in thecompression system 100 may provide one or more advantages. For example,the high density and high heat capacity or volumetric heat capacity ofcarbon dioxide with respect to other process fluids may make carbondioxide more “energy dense.” Accordingly, a relative size of thecompression system 100 and/or the components thereof may be reducedwithout reducing the performance of the compression system 100.

The carbon dioxide may be of any particular type, source, purity, orgrade. For example, industrial grade carbon dioxide may be utilized asthe process fluid without departing from the scope of the disclosure.Further, as previously discussed, the process fluids may be a mixture,or process fluid mixture. The process fluid mixture may be selected forone or more desirable properties of the process fluid mixture within thecompression system 100. For example, the process fluid mixture mayinclude a mixture of a liquid absorbent and carbon dioxide (or a processfluid containing carbon dioxide) that may enable the process fluidmixture to be compressed to a relatively higher pressure with lessenergy input than compressing carbon dioxide (or a process fluidcontaining carbon dioxide) alone.

FIG. 6 is a flowchart depicting an exemplary method 300 for compressinga process fluid, according to one or more embodiments. The method 300may include driving a rotary shaft of a supersonic compressor via adriver operatively coupled with the supersonic compressor, as at 302.The drive shaft may be driven by a driver, such as, for example, anelectric motor.

The method 300 may also include establishing a fluid property of theprocess fluid flowing through an inlet passageway defined by an inlet ofthe supersonic compressor via at least one moveable inlet guide vanepivotally coupled to a housing of the supersonic compressor andextending into the inlet passageway, the process fluid including carbondioxide, as at 304. The method may also include adjusting the at leastone moveable inlet guide vane to establish the fluid property of theprocess fluid, where the fluid property is a flow pattern, a firstvelocity, a mass flow rate, a pressure, or a temperature.

The method 300 may further include rotating a centrifugal impellermounted about the rotary shaft, such that the process fluid flowingthough the inlet passageway of the supersonic compressor is drawn intothe centrifugal impeller and discharged from a tip of the centrifugalimpeller via a plurality of flow passages, the discharged process fluidhaving a supersonic velocity with an exit absolute Mach number of aboutone or greater, as at 306. The method 300 may also include flowing thedischarged process fluid having a supersonic velocity through an annulardiffuser passageway defined by a static diffuser and fluidly coupled tothe plurality of flow passages such that a pressure energy of thedischarged process fluid is increased, thereby compressing thedischarged process fluid at a compression ratio of about 8:1 or greater,as at 308.

The static diffuser may be a vaneless diffuser bounded in part by ashroud wall and a hub wall defining the annular diffuser passagewaytherebetween. The shroud wall bounding the annular diffuser passagewaymay be a straight wall, a contoured wall, or a combination thereof, andthe hub wall bounding the annular diffuser passageway may be a straightwall, a contoured wall, or a combination thereof. In another embodiment,the static diffuser may be a vaned diffuser bounded in part by a shroudwall and a hub wall defining the annular diffuser passagewaytherebetween, and the vaned diffuser may include a plurality of lowsolidity diffuser vanes extending into the annular diffuser passagewayfrom either or both the shroud wall and the hub wall.

It should be appreciated that all numerical values and ranges disclosedherein are approximate valves and ranges, whether “about” is used inconjunction therewith. It should also be appreciated that the term“about,” as used herein, in conjunction with a numeral refers to a valuethat is +/−5% (inclusive) of that numeral, +/−10% (inclusive) of thatnumeral, or +/−15% (inclusive) of that numeral. It should further beappreciated that when a numerical range is disclosed herein, anynumerical value falling within the range is also specifically disclosed.

Certain embodiments and features have been described using a set ofnumerical upper limits and a set of numerical lower limits. It should beappreciated that ranges including the combination of any two values,e.g., the combination of any lower value with any upper value, thecombination of any two lower values, and/or the combination of any twoupper values are contemplated unless otherwise indicated.

The foregoing has outlined features of several embodiments so that thoseskilled in the art may better understand the present disclosure. Thoseskilled in the art should appreciate that they may readily use thepresent disclosure as a basis for designing or modifying other processesand structures for carrying out the same purposes and/or achieving thesame advantages of the embodiments introduced herein. Those skilled inthe art should also realize that such equivalent constructions do notdepart from the spirit and scope of the present disclosure, and thatthey may make various changes, substitutions and alterations hereinwithout departing from the spirit and scope of the present disclosure.

We claim:
 1. A supersonic compressor comprising: a housing; an inletcoupled to or integral with the housing and defining an inlet passagewayconfigured to receive and flow therethrough a process fluid; a pluralityof inlet guide vanes coupled to the housing and extending into the inletpassageway; a rotary shaft configured to be driven by a driver; acentrifugal impeller coupled with the rotary shaft and fluidly coupledto the inlet passageway via a plurality of flow passages formed by thecentrifugal impeller, the centrifugal impeller having a tip andconfigured to impart energy to the process fluid received via the inletpassageway and to discharge the process fluid from the tip via theplurality of flow passages in at least a partially radial direction atan exit absolute Mach number of about one or greater; a balance pistonconfigured to balance an axial thrust generated by the centrifugalimpeller; a static diffuser circumferentially disposed about the tip ofthe centrifugal impeller and bounded in part by a shroud wall and a hubwall defining an annular diffuser passageway therebetween, the staticdiffuser configured to receive the process fluid from the plurality offlow passages of the centrifugal impeller and convert, within theannular diffuser passageway, the energy imparted; and a collectorfluidly coupled to the annular diffuser passageway and configured tocollect the process fluid exiting the annular diffuser passageway,wherein the supersonic compressor is configured to provide a compressionratio of at least about 8:1.
 2. The supersonic compressor of claim 1,wherein: the plurality of inlet guide vanes are pivotably coupled to thehousing; the balance piston is integral with the centrifugal impeller;and the collector is a discharge volute configured to discharge theprocess fluid to a downstream processing component.
 3. The supersoniccompressor of claim 2, wherein the plurality of inlet guide vanes areconfigured to condition the process fluid flowing therethrough to yieldone or more predetermined fluid properties selected from the groupconsisting of a flow pattern, a velocity, a mass flow rate, a pressure,and a temperature.
 4. The supersonic compressor of claim 1, wherein: thesupersonic compressor is configured to provide a compression ratio of atleast about 10:1; the process fluid comprises carbon dioxide; thecentrifugal impeller is configured to discharge the process fluid fromthe tip via the plurality of flow passages in at least a partiallyradial direction at an exit absolute Mach number of about 1.3 orgreater; and the centrifugal impeller is further configured to rotatevia the rotary shaft at a rotational speed of about 500 meters persecond or greater.
 5. The supersonic compressor of claim 1, wherein thestatic diffuser is a vaneless diffuser configured to discharge theprocess fluid flowing therethrough at a subsonic velocity.
 6. Thesupersonic compressor of claim 1, wherein the centrifugal impellercomprises a hub and a plurality of blades extending therefrom andforming the plurality of flow passages, each of the plurality of bladescomprising a leading edge and at least one leading edge of the pluralityof blades is meridionally spaced from at least one other leading edge ofthe plurality of blades.
 7. The supersonic compressor of claim 1,further comprising a shroud having an abradable material disposedadjacent a plurality of blades extending from a hub of the centrifugalimpeller.
 8. The supersonic compressor of claim 1, wherein the processfluid comprises carbon dioxide.
 9. The supersonic compressor of claim 8,wherein the process fluid comprises about ninety percent carbon dioxide.10. The supersonic compressor of claim 1, wherein the centrifugalimpeller is an open-faced impeller.
 11. A compression system comprising:a driver comprising a drive shaft, the driver configured to provide thedrive shaft with rotational energy; a supersonic compressor operativelycoupled to the driver via a rotary shaft integral with or coupled withthe drive shaft, the supersonic compressor comprising: a compressorchassis; an inlet defining an inlet passageway configured to flow aprocess fluid therethrough, the process fluid having a first velocityand a first pressure energy; a plurality of inlet guide vanes pivotallycoupled to the compressor chassis and extending into the inletpassageway; a centrifugal impeller coupled with the rotary shaft andfluidly coupled to the inlet passageway via a plurality of flow passagesformed by the centrifugal impeller, the centrifugal impeller having atip and configured to increase the first velocity and the first pressureenergy of the process fluid received via the inlet passageway and todischarge the process fluid from the tip via the plurality of flowpassages in at least a partially radial direction having a secondvelocity and a second pressure energy, the second velocity being asupersonic velocity having an exit absolute Mach number of about one orgreater; a static diffuser circumferentially disposed about the tip ofthe centrifugal impeller and defining an annular diffuser passagewayfluidly coupled to the plurality of flow passages, the annular diffuserpassageway configured to receive and reduce the second velocity of theprocess fluid to a third velocity and increase the second pressureenergy to a third pressure energy, the third velocity being a subsonicvelocity; and a discharge volute fluidly coupled to the annular diffuserpassageway and configured to receive the process fluid flowingtherefrom, wherein the supersonic compressor is configured to provide acompression ratio of at least about 8:1.
 12. The compression system ofclaim 11, wherein the supersonic compressor further comprises: a shroudhaving an abradable material disposed adjacent a plurality of bladesextending from a hub of the centrifugal impeller and forming theplurality of flow passages fluidly coupled to the annular diffuserpassageway and the inlet passageway; and a balance piston integral withthe centrifugal impeller and configured to balance an axial thrustgenerated by the centrifugal impeller, wherein the supersonic compressoris configured to provide a compression ratio of at least about 10:1, theprocess fluid comprises carbon dioxide, and the second velocity has anexit absolute Mach number of about 1.3 or greater.
 13. The compressionsystem of claim 11, wherein the static diffuser is a vaneless diffuserbounded in part by a shroud wall and a hub wall defining the annulardiffuser passageway therebetween.
 14. The compression system of claim13, wherein either or both the shroud wall and the hub wall arecontoured, such that an axial width of the annular diffuser passagewayis reduced as the shroud wall and the hub wall extend radially outward.15. The compression system of claim 11, wherein the static diffusercomprises a plurality of low solidity diffuser vanes extending into theannular diffuser passageway.
 16. The compression system of claim 15,wherein the static diffuser is bounded in part by a shroud wall and ahub wall defining the annular diffuser passageway therebetween, and theplurality of low solidity diffuser vanes are arranged in tandem withinthe annular diffuser passageway and extend into the annular diffuserpassageway from the shroud wall, the hub wall, or both the shroud walland the hub wall.
 17. A method for compressing a process fluid,comprising: driving a rotary shaft of a supersonic compressor via adriver operatively coupled with the supersonic compressor; establishinga fluid property of the process fluid flowing through an inletpassageway defined by an inlet of the supersonic compressor via at leastone moveable inlet guide vane pivotally coupled to a housing of thesupersonic compressor and extending into the inlet passageway; rotatinga centrifugal impeller mounted about the rotary shaft, such that theprocess fluid flowing though the inlet passageway of the supersoniccompressor is drawn into the centrifugal impeller and discharged from atip of the centrifugal impeller via a plurality of flow passages, thedischarged process fluid having a supersonic velocity with an exitabsolute Mach number of about 1.0 or greater; and flowing the dischargedprocess fluid having a supersonic velocity through an annular diffuserpassageway defined by a static diffuser and fluidly coupled to theplurality of flow passages such that a pressure energy of the dischargedprocess fluid is increased, thereby compressing the discharged processfluid at a compression ratio of about 8:1 or greater.
 18. The method ofclaim 17, further comprising: adjusting the at least one moveable inletguide vane to establish the fluid property of the process fluid, whereinthe fluid property is selected from the group consisting of a flowpattern, a first velocity, a mass flow rate, a pressure, and atemperature, and wherein the process fluid comprises carbon dioxide. 19.The method of claim 17, wherein: the static diffuser is a vanelessdiffuser bounded in part by a shroud wall and a hub wall defining theannular diffuser passageway therebetween, the shroud wall bounding theannular diffuser passageway is a straight wall, a contoured wall, or acombination thereof, and the hub wall bounding the annular diffuserpassageway is a straight wall, a contoured wall, or a combinationthereof.
 20. The method of claim 17, wherein: the static diffuser is avaned diffuser bounded in part by a shroud wall and a hub wall definingthe annular diffuser passageway therebetween, and the static diffusercomprises a plurality of low solidity diffuser vanes extending into theannular diffuser passageway from either or both the shroud wall and thehub wall.